This invention relates to air bag closures and more particularly to dual door arrangements that are pushed open by the inflating air bag to create an opening for deployment of the air bag into the passenger compartment of a vehicle.
Such a dual door arrangement is generally disclosed in U.S. Pat. No. 4,968,057 granted Nov. 6, 1990 to Scott Rafferty for a cover assembly for an air bag unit. The cover assembly disclosed in this patent has two separate and distinct door members that form an open styling line when the door members are in the closed position as shown by solid lines in the patent drawings. The door members are mounted in the closed position by flanges of their respective sheet metal plates that are riveted to a rectangular frame. The flanges form bends that act as hinges for swinging the door member to an open position when the air bag inflates and pushes against the door members. The door members include separate decorative panels comprising elastomer cores and outer shells that are carried by their respective sheet metal plates. The metal plates, with their attached decorative panels, are separate and distinct in what may be termed a "visible" door arrangement. Because of the separate nature of the door members, the Rafferty cover assembly includes a substrate that is bonded to the back of the metal plates 44 to prevent separation of their adjacent ends and undesirable widening of the open styling line between the door members.
U.S. Pat. No. 4,082,310 granted Jan. 21, 1992 to David J. Bauer for an arrangement for providing an air bag deployment opening also discloses the use of sheet metal doors that include integral bendable hinge sections as shown in FIG. 9 of the patent drawing. The adjacent ends of the doors, however, are joined by a frangible hat shaped bridging and the joined doors are covered by a common decorative panel comprising a foam plastic layer and a skin layer. The doors are further joined by a stiffener that is bonded to the back of the doors. This is an "invisible" door arrangement that requires slitting and tearing the decorative panel to create an opening for air bag deployment. Such an opening is created in the arrangement by the air bag impacting against the back of the doors to split the stiffener, bridging section and decorative panel apart and then propagate an opening in the decorative panel as the doors are pushed to an open position by the air bag.